Method of and apparatus for forming metal



R. GILLIS March 11, 1941.

METHOD OF AND APPARATUS FOR FORMING METAL Filed Dec. 7, 1939 2 Sheets-Sheet 1 FIG. I

INVEWTOR R. GILL/S A T TORNEY March 11, 19-41.

R. GILLIS METHOD OF AND APPARATUS FOR FORMING METAL Fiied Dec. 7, 1959 2 Sheets-Sheet 2 ATTORNEY Patented Man 11, 194i UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR FORMING METAL Randall Gillis, Westfield, N. J., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December '1, 1939, Serial No. 308,031

' 14 Claims. (01. 29-33) This invention relates to a method of .and apparatus for forming metal, and more-particularly to a method of and apparatus for formin metal into a seamless tube or into a seamless tubular sheath about an elongated core by simultaneously casting and forging the metal.

Many varieties of electrical conductor cables .used in the communications arts and. in arts having to do with power distribution have cor'es including conductor strands and electrically insulating sheaths, which cores are enveloped in seamless, snugly fitting sheaths of metal, ordinarily lead, or lead alloy. In most instances these sheaths are formed in situ on the core by extruding the metal to form than through a suitable die while the core is being advanced through the die also. Concentricity of the sheath on the core, 1. e. uniformity of thickness of the sheath circumferentially about the core, and uniformity of thickness of the sheath along the core are sometimes difiicult to maintain in the extrusion process of forming the sheath, since variations in the fluidity of the material being extruded, as

it passes through the die, on opposite sides of the time, may cause the sheath to become thicker on one side than on the other.

One object of the present inventionis to provide a simple and reliable method of forming a seamless sheath about an elongated core in a prising steps of casting the sheath about the 40 core with an excessive diameter and of reducing the diameter, the process of casting merging inseparably into the process of reducing the diameter.

Another embodiment of the invention may be 45 in an apparatus for forming a sheath on an elongated; advancing core passing therethrough comprising a tapering mold to receive molten sheathing material and having one wall thereof movable with respect to the other .to simultaneously I 50 mold and forge the sheath material about a core. Other objects and features of the invention will appear from the following detailed description of an apparatus constructed in accordance with the invention for carrying on the method 55 of the invention, taken in connection with the accompanying drawings in which the same reference numerals are applied to identical parts in the several figures and in which Fig. 1 is a view in side elevation and partly in vertical central section of an apparatus con- 5 structed in accordance with the invention;

Fig. 2 is a plan view thereof Fig. 3 is an enlarged view in vertical central section of the combined casting mold and forging members; and

Fig. 4 is a view, similar to Fig. 3, of a modified form.

As herein disclosed, the primary'essentials of the invention are best shown in Fig. 3, the associated parts and devices shown in Figs. 1 and 2 15 being ancillary. There is stationary convex casting and forging member 20 of a generally conical form, about which is positioned a complementary concave, conically hollow; coaxially positioned, reciprocable casting and forging member 2 I. latter has -a cylindrical outer surface to fit sildably into a cylinder or sleeve 22 supported and mounted on a base or pedestal 23. The sta-. tionary member 2|] is rigidly mounted in the left end of the cylinder 22, as by screws 24, while the 25 member 2| extends out beyond the right end of the cylinder and is there provided with an enlarged circumferential shoulder 25. As here shown the conical outer surface 26 of the fixed member 20 and the conical inner surface 21 of 30 the reciprocable member 2| have the same apical angle, so that these surfaces are always parallel to each other. While thisis the prefer-red construction, there may also be instances in which the apical angles of the two cones are made to difier more or less, so that the space defined between the two surfaces is not then of equal width in all parts, as is the case in the drawings.

The member .20 is formed with an axial bore 28, and the member 2| may be formed with an axial bore 29. The bore 28 is dimensioned to receive and pass a cylindrical, elongated core I! which is to be provided with a seamless continuous sheath I8, e. g. of lead or lead alloy. The bore 29 has a diameter to match the predetermined outer dimensions of the sheath. In most .instances the length of the bore 29 will be vanishingly small.

The member 20 is further formed within its mass with a coaxial chamber 30, and the member 2! is provided with a similar chamber 3|. These chambers may each be cylindrical as at 30 or conical as at 3|, as may be dictated by the mass of the members in which they are. A suitable temperature regulating fluid, water, oil,

The 20- steam, air, or the like is circulatedthrough these chambers by means of pipes. and 33 commu nicating therewith from sources not shown. Lubricating oil or other .fluid may be fed to the surface 26 through pipes 34 and passages 36 and to the surface 21 through pipes 35 and passages 31.

Anelectrical heating element 38 may be located, if desired, around the left end of the member 20 in the annular chamber at the left of the left end of the member 2|. This heating element may be fed with electric current through leads 39 from any suitable source not shown. 7

A melting tank or supply tank 40 is supported above the sleeve 22 in any suitable fashion and has adelivery pipe 4| opening from its bottom into the annular chamber at the, left of the member 2|. There may {be an electrical heatin device 42 in the tank All to melt or to keep molten its contents, fed from any suitable source of electric current not shown.

Generally parallel links 43 are pivotably secured to opposite sides of the shoulder 25 at one end, at the other end, are journalled on cams or eccentrics on a transverse shaft 44 journalled in pillars 45. The shaft also has a fly-wheel 46 and a driving pulley 41. The pulley 41 is driven by belts 48 from a motor 49. A'clutch device 50 of any suitable construction and actuable by 'a treadle serves to couple the fly-wheel 46 and pulley 41 to the shaft at will.

In operation, material for the cable sheath, e. g. lead or a suitable lead'alloy, may be melted in the tank 40 or brought molten to the tank and stored therein. A core I9 to be sheathed enters through the bores 28 and 29 from any suitable supply not shown. The sheath and core |9 emerging from the bore 29 are drawn to the right by any suitable means not shown. The molten sheath material flows down through the pipe 4| into the annular chamber around the left end of the member 20 and thence into the conically tapering, parallel walled space between the members 20 and 2|. The heat exchange between the 3 hot material entering from the pipe 4| and the actuated to couple the fly-wheel and drive to the shaft 44 which then, through its cams and thelinks 43, drives the member 2| in rapid, brief reciprocation inside of the sleeve 22 with respect to the member 20. The result is that the distance between the mold faces 26 and 21 which .form and shape the sheath is pulsatingly varied.

The movable face or wall 2'! of the mold moves in a direction having components both perpendicular and parallel to the opposite fixed face or wall 26. Thus the material, solidifying slowly as it passes between these faces is subjected to a continuous pulsating forging effect. It is both cast and forged; and the one merges into the Verse these relations are believed to be too obsions as it leaves the members 2|! and 2| and is simultaneously applied to the core. Hence the thickness of the sheath at every point is already determined when the sheath meets the core, determined by the members 20 and 2|, and cannot 5 vary either circumferentially or longitudinally. The sheath is positively controlled to be concentric with the core and uniform along it.

Since-the core plays no' part in forming the sheath, the apparatus may be modified, as shown in Fig. 4, for the manufacture of seamless tubing of unlimited length, which will not only have no longitudinal seam but will also be free from circumferential joints, seams 'or welds of any kind. 7 v The apparatus disclosed in Fig. 4 is identically like that already described in all respects, except that the stationary mold member I26 has no axial bore, since no core such as H! is now under.

consideration. The conical body of the member 9 terminates in a short cylindrical nose or mandrel I29 to aid the pipe 8 being drawn from between the members I26 and 2| from collapsing under the tensile stress .of being pulled away. To assist further in fully hardening the pipe, this nose or mandrel I29 maybe pro ed with an individual cooling water chamber and supply pipes 53 whereby to thoroughly chill the formed p pe. v

In the embodiments herein disclosed, the convex mold member 20 or I20 is shown. as fixed,

while the concavemold member 2| is shown as reciprocable. The modifications required to revious to require description or illustration. Also, while the invention is particularly described as applied to the case of sheathing a cable core with lead or lead alloy, it may also be used for other materials, for example for artificial plastics which are capable of being melted, cast and forged in the same way. In general, the embodiments of the invention herein disclosed are illustrative and may be modified and varied in many ways with out departing from the spirit and scope of the invention as set forth in and limited only by the appended claims.

What is claimed is:

1. The method of forming material which comprises-the steps of advancing molten material in a continuous elongated body, cooling the advancing body to convert the material thereof progressively from fluid to plastic to solid, and simultaneously forging that part of .the progressively cooled material in which the change from fluid to plastic to solid is proceeding.

2. The method of forming material which co prises the steps of advancing molten material in a continuous elongated body, cooling the advancing body to convert the material thereof progressively from fluid to plastic to solid, and simultaneously subjecting the progressively cooled material to pulsating pressure to forge that partof the same in which the change from fluid to plastic to solid is proceeding.

3. In an apparatus for forming material, means to confine and form advancing molten material into a continuous elongated body, means to cool the advancing body to convert the material thereof progressively from fluid to plastic to solid, and means to simultaneously forge that part of the progressively cooled material in which the 7 change from fluid to plastic to solid is proceeding.

4. In an apparatus for forming material, means to confine and form advancing molten material 76' into a continuous elongated body, means to cool the advancing body to convert the material thereof progressively from fluid to plastic to solid, and means to simultaneously subjectv the progressively cooled material to pulsating pressure to forge that part of the same in which the change from fluid to plastic to solid is proceeding.

5-. In an apparatus for forming material, a mold having side walls and an open end, means to supply molten material to be formed to the mold to passtherethrough and out through the open end, and means to pulsingly vary the distance between two side walls of the mold to forge material passing therebetween.

6. In an apparatus for forming material, a mold having side walls and an open end, means 'to supply molten material to be formed to the mold to pass therethrough and out through the open end, means to control the temperature of the side walls to progressively cool material passing through the mold from fluid to plastic to solid, and means to pulsingly vary the distance between two side walls of the mold to forge ma-. terial passing therebetween while the change from fluid to plastic to solid is proceeding.

'7. In an apparatus for forming material, a mold for continuous casting of molten material comprising a fixed wall on one side of the mold cavity, and a movable wall on the other side of the mold cavity, in combination with means to reciprocate the movable wall toward and from the fixed wall to forge material passing between the walls while the material is cooling.

8. In an apparatus for forming material, a

'mold for continuous casting of molten materialcomprising a fixed wall on one side of the mold cavity, and a movable wall on the other side of the mold cavity, in combination with means to reciprocate the movable wall in a direction having components both perpendicular and parallel ,g to the fixed wall to forge material passing between the walls while the material is cooling.

9. In an apparatus for forming material, a

member havinga convex mold cavity surface thereon, and a member having a completely OOH. cave mold cavitysurface thereon, in combination 1 with means to pulsingly varythe distance between the two surfaces to force material in the mold space between the two surfaces while the material is cooling from fluid to plastic to solid.

10. In an apparatus for formingmaterial, a member having a convex mold cavity surface thereon, and a member having a complementary concave mold cavity surface thereon, in combination with means to reciprocate one of the members to pulsingly vary the distance between the two surfaces'to force material in the mold space between the two surfaces while the material is cooling from fluid to plastic to solid.

11. In an apparatus for forming material, a

guide member, a first mold member fixedly mounted thereon, a second mold member reciprocable in the guidemember toward and from the first member, a convex mold surface upon one of the mold members and a concave mold 1 surface upon the other mold member defining a mold cavity therebetween, and means to reciprocate the second-mold member to pulsingly vary the distance between the two moldsurfaces.

12. In an apparatus to form. material into a 1 hollow elongated body, a convex tapered member, a complementary concave tapered member coaxial thereto and cooperating therewith to define a conical annular mold cavity therebetween, means to supply molten material to the large end of the mold cavity, and means to reciprocate one of the members with respect to the other to pulsingly vary the distance therebetween to' I force material in the cavity while the material is cooling from fluid to'plastic to solid.- 7

elongated 13. In an apparatus for sheathing an core, a first mold member having a bore there.- in to receive and pass an advancing core, a second mold member to coact therewith and hav- I ing an aperture to receive and pass the core and a sheath thereon, two mold'surfaces one on each member defining an annular mold cavity therebetween and coaxial with the core, means to supply molten sheath material to the cavity, and

means to reciprocate one of the mold members with respect to the other mold member to force the material, in the cavity into a-sheath about the core while the .material passing through the mold changes from fluid to plastic to solid;

14. In an apparatus for sheathing an elongated core, a first mold member having a bore therein to receive and pass an advancing core, a second mold member to coact therewith and having an aperture to receive and pass the core and a sheath thereon, two mold surfaces one on each member defining an annular mold cavity therebetween and coaxial with the core, means to supply molten sheath material to the cavity, means to control the temperatures ofthe two mold members to cause sheath material passing through the mold cavity to change progressively from fluid to plastic to solid, and means to reciprocate one of the mold members with respect to the other mold member to forge the material in the cavity into a sheath about the core while "the material passing through the mold changes from fluid to plastic to solid. 7

' ALL GILLIS. 

